/**
 *  文件名: CharsetFilter.java
 *  功  能: 中文过滤器
 *  作  者: 秦震
 *  日  期: 2007-11-25
 *  版  权: 秦震
 *  备  注: 
 */
package com.ddj.struts.filter;

import javax.servlet.*;
import java.io.IOException;

	/**
	 * 字符转换，使用utf-8格式的模板，模板中有非英文字符，请使用字符过虑功能
	 * 需要在Web.xml文件中设置，设置形式如下：
	 * <filter>
	 * <filter-name>CharsetFilter</filter-name>
	 * <filter-class>com.ddj.filter.CharsetFilter</filter-class>
	 * <init-param>
	 * <param-name>encoding</param-name>
	 * <param-value>utf-8</param-value>
	 * </init-param>
	 * <init-param>
	 * <param-name>ignore</param-name>
	 * <param-value>true</param-value>
	 * </init-param>
	 * </filter>
	 * <filter-mapping>
	 * <filter-name>CharsetFilter</filter-name>
	 * <url-pattern>*.do</url-pattern>
	 * </filter-mapping>
	 * <filter-mapping>
	 * <filter-name>CharsetFilter</filter-name>
	 * <url-pattern>*.jsp</url-pattern>
	 * </filter-mapping>	
	 * @author chen
	 */

	public class CharsetFilter implements Filter {
		
	protected String encoding = null;

	protected FilterConfig filterConfig = null;

	protected boolean ignore = true;

	public void destroy() {

		this.encoding = null;
		this.filterConfig = null;

	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		if (ignore || (request.getCharacterEncoding() == null)) {
			String encoding = selectEncoding(request);
			if (encoding != null)
				request.setCharacterEncoding(encoding);
		}
		chain.doFilter(request, response);
	}

	public void init(FilterConfig filterConfig) throws ServletException {

		this.filterConfig = filterConfig;
		this.encoding = filterConfig.getInitParameter("encoding");
		String value = filterConfig.getInitParameter("ignore");
		if (value == null)
			this.ignore = true;
		else if (value.equalsIgnoreCase("true"))
			this.ignore = true;
		else if (value.equalsIgnoreCase("yes"))
			this.ignore = true;
		else
			this.ignore = false;
	}

	protected String selectEncoding(ServletRequest request) {
		return (this.encoding);
	}
}